The present invention relates to a sensitive medium cleaner for use in an electrophotographic copying machine. More particularly it is directed to an improvement wherein a cleaning unit, which is equipped with a cleaning blade for scraping off post-development toner from a sensitive medium and a conveying roller for collecting the toner into a collection sump, is pressed against the sensitive medium with a fixed pressure only during the operation of the copying machine or is separated from the sensitive medium surface at the stop of the copying machine.
In the conventional sensitive medium cleaners having a cleaning blade and a conveying roller pressed against the surface of a sensitive medium, the sensitive medium can be stopped at a position wherein the cleaning blade and conveying roller come to rest against portions of the sensitive medium which do not image the copy paper. In an alternative copying machine the cleaning blade alone is pressed against the sensitive medium during the copying machine operation. The conveying roller is disposed spaced from the sensitive medium surface and is charged at a polarity opposite to that of the toner so as to attract the toner electrostatically for collection. With the sensitive medium cleaner of such a machine, there exist disadvantages including high manufacturing cost.
U.S. Pat. Nos. 3,740,789 to Ticknor and 3,871,762 to Ulasakker are illustrative of sensitive medium cleaners employing a cleaning blade and collecting roller.